Prior to his time as a political analyst, Sabato worked for nine years with Virginia Democratic politician Henry Howell. At the age of 15, Sabato joined Howell's first campaign for the Virginia governorship in 1968, and then worked on his successful run for lieutenant governor in 1971, and his campaigns for governor in 1973 and 1977.[3]

Before becoming an academician at the University of Virginia, Sabato had already established a reputation as a published expert on the rise of two-party politics in the Southern United States, particularly with his 1977 publication of The Democratic Party Primary in Virginia: Tantamount to Election No Longer.[5] See also Solid South and tantamount to election.

In 1978, Sabato became a member of the faculty at the University of Virginia. Sabato has engaged in 30 years of research and taught more than 14,000 students.[2]

He is a University Professor and the Robert Kent Gooch Professor of Politics at the University of Virginia.[4]

In 2005, Sabato made a $1 million contribution to UVA, the largest gift ever given by a faculty member.[2]

Sabato has authored over twenty books on politics; his best-known volumes include Feeding Frenzy: Attack Journalism and American Politics and The Rise of Political Consultants: New Ways of Winning Elections.

In January 2011, he published Pendulum Swing, which analyzed the 2010 midterm elections and the potential effect of Republican victories on the 2012 presidential, congressional, and state-level elections.[6]

Prior to Pendulum Swing, Sabato authored The Year of Obama in 2009 and A More Perfect Constitution in 2007, which discussed his ideas for amending the U.S. Constitution. Other Sabato books include The Sixth Year Itch: The Rise and Fall of the George W. Bush Presidency, Divided States of America: The Slash and Burn Politics of the 2004 Presidential Election, and Get in the Booth! A Citizen's Guide to the 2004 Election. He also issues a political newsletter, Sabato's Crystal Ball. He has written textbooks used by high school and college American government classes. He has been a frequent guest analyst on cable news outlets as well as radio programs.

He has published a new book, The Kennedy Half-Century: The Presidency, Assassination, and Lasting Legacy of John F. Kennedy.[7] The book was released by Bloomsbury USA, New York on October 15, 2013. It focuses on John F. Kennedy's life, administration, and assassination and contains research from focus groups, polling, and interviews with key players and eyewitnesses.

Sabato's Crystal Ball is run by the University of Virginia Center for Politics in Charlottesville. The site contains up-to-date analysis of an array of political races around the United States. It developed from an effort to inform and motivate the nation's citizens about the political process. It follows presidential elections, as well as each Senate, House, and gubernatorial contest. The Crystal Ball is a free public service intended to interest both the average voter and political junkies.

Prior to the 2002 midterm elections, where the Republican Party saw gains in both branches of Congress, Sabato's Crystal Ball website accurately predicted the outcome in 433 of the 435 contests for the House of Representatives and 32 of 34 Senate races.[8]

In 2004, which saw Republicans retain the White House and gain seats in the House and Senate, Crystal Ball correctly predicted the outcome of 525 of the 530 political races (99% accuracy), missing only one House race, one Senate race, one governor's race and two states in the Electoral College.[9]

In August 2006, Crystal Ball predicted that the Democrats would gain 29 seats in the House of Representatives and 6 seats in the Senate, providing them with a majority in both chambers. Sabato's predictions proved correct: each of his 33 Senate predictions were accurate, and in the House, Democrats gained 29 seats on election night, the precise total predicted by the Crystal Ball (Democrats would go on to pick up a 30th seat in the December 12, 2006 run-off in Texas' 23rd district).[10]

In 2006 Sabato was named the most accurate prognosticator by MSNBC, CNBC, and Pew's Project for Excellence in Journalism. In 2006, Sabato was the only national analyst who correctly predicted the exact Democratic gains in Senate and House contests.[10]

In July 2008, Crystal Ball correctly projected that Barack Obama would win the presidency in a near-landslide.[11] Sabato predicted a 364-174 margin in the Electoral College, as well as the popular vote percentages.[12] The prediction was merely one point off the mark, with the actual result on November 4, 2008 being Obama 365 and McCain 173. (It did not predict an Obama win in Nebraska's 2nd congressional district.) Crystal Ball also accurately predicted 100% of all 35 Senate races, and 11 gubernatorial races correctly.[13]

In November 2010, Crystal Ball projected that Republicans would pick up 55 seats in the House of Representatives.[14] The Republicans picked up 63 House seats. It predicted a pickup of 8 seats in the Senate for Republicans.[15] The Republicans picked up 6 Senate seats.[16]

In 2012, Crystal Ball projected that Obama would win the presidency with 290 electoral votes to 248 for Romney; there would be no change in partisan makeup of the Senate, with Democrats at 53 and Republicans at 47; and Democrats would pick up 3 seats in the House of Representatives, for a result of 239 Republicans and 196 Democrats.[17] The projection was similar to the actual results, but Crystal Ball under-estimated Obama's number of electoral votes (332) and under-estimated Democratic victories in both the Senate (Democrats picked up two seats) and in the House (Democrats picked up eight seats).

The extensive use of Sabato as a "Dr. Dial-a-Quote"[18] has been noted in political media circles and attributed to his easy quotability and ability to offer pronouncements on a wide variety of topics.[3] The Wall Street Journal refers to Sabato as "probably the most quoted college professor in the land"[1][4] and some members of the news media have a rhyme referring to Sabato's availability for a quick quip on politics: "Need a quote/Do not tarry/Call U-Va./And ask for Larry."[19]

The number of times he has been quoted annually has risen dramatically over the years: 78 times in 1992; 122 times in 1996; 179 in 2000; and 344 times in 2004.[2] A 1996 New Republic article found that over the course of just one month, Sabato had been quoted as an expert on a large range of political topics: "Perot's exclusion from the debates, Clinton's policy toward Iraq, Whitewater, Dole's attitude toward pot-smoking, Dick Morris, negative ads, (and) the continued relevance of political parties."[2]

His ability to speak on a wide range of topics had led to a similarly wide range of titles for Sabato, including: "an expert on political scandals" in an article about misdeeds in the Ohio GOP, a "congressional expert" when writing about a congressional election, an "expert on presidential affairs" when writing about a presidential visit, and "an expert in opinion and opinion making" when discussing Katie Couric's declining ratings.[20]

In June 2009, it was revealed that Sabato's Center for Politics had been the recipient of over seven million dollars in earmark money from Congressman Virgil Goode, whom Sabato predicted would win re-election in 2008, despite declining poll numbers; Goode ultimately lost the race by fewer than 800 votes out of about 316,000 votes cast.[21] One observer suggested that Sabato should have revealed his Center's financial connection to Goode or recused himself from making predictions about the race.[22]